Slide #113TITLE: Crates' Globe
DATE: 180-150 B.C.
AUTHOR: Crates of Mallos
DESCRIPTION: These slides show modern reconstructions of the
globe of Crates of Mallos, which was originally constructed at Pergamum
in Asia Minor in 180 B.C. The various measurements of the earth's size
by Eratosthenes raised a curious problem. The known dimensions of the oikumene
[inhabited world] were too small relative to the estimated size of the
earth sphere, the oikumene occupied only one quadrant of the sphere.
Such an imbalance in a spherical object was contrary to the Greek sense
of symmetry. Crates, therefore, solved the problem on his globe by drawing
three other "continents " (an anticipation/prediction of the existence
of the Americas, Antarctica and Australia) to provide the necessary "balance"
and symmetry. Here was born the concept of the "Antipodes", or the great
southern continent, the "Terra Australis", that would be conjured up in
medieval and renaissance period maps.

It appears to have been the polymath grammarian Crates of Mallos, a
contemporary of Hipparchus, and a member of the Stoic School of Philosophers,
who made the first recorded attempt to construct a terrestrial globe, and
that he exhibited the same in Pergamum, not far from the year 150 B.C.
About 168 B.C. Crates, who wrote among other things on Homer and the wanderings
of Odysseus, visited Rome. He was professionally interested in the city's
drainage system, but while exploring the Cloaca Maxima broke his leg. He
used the period of recovery to give lectures in Rome, which are said to
have created a great impression. His view of terrestrial mapping was that
the shape could only be right if it was drawn on a globe, and eventually
that the scale could only be effective if the globe was at least ten feet
in diameter. In designing his 'orb', if indeed he put his theory into practice,
Crates favored an unusual form of symmetry. There were, he said, separated
by two intersecting belts of ocean, four symmetrical landmasses: (a) Europe,
Asia and the part of Africa known at that time; (b) south of them, that
of the
Antoikoi, 'dwellers opposite'; (c) west of them, the Perioikoi,
'dwellers round'; (d) south of the Perioikoi, the Antipodes.
The break between the landmass known at that time and that of the Antoikoi
came, according to him, at a belt on each side of the equator, and there
were Ethiopians (Aethiopes, 'black-faces') on each side of
this water divide. Homer had written of the Ethiopians, split in
two, some in the East, some by the setting sun. Later Greek writers interpreted
this passage in various ways. No doubt, as a Homeric scholar, Crates was
more concerned to give a plausible account of Homeric descriptions than
to investigate explanations which suggested the existence of a continuous
African landmass stretching across the equator. The idea however, was taken
up by Cicero in the somnium Scipionis [ 'Dream of Scipio'] which
he incorporated in his De republica. When Macrobius wrote a commentary
on the somnium Scipionis about AD 390, he defended and amplified
Crates' theory, aspects of which thus found their way into medieval cartography;
the Perioikoi and Antipodes were then omitted, although discussed
by Cicero and Macrobius.

It seems to have been Crates' idea that the earth's surface, when represented
on a sphere, should appear as divided into four island-like habitable regions.
On the one hemisphere, which is formed by a meridional plane cutting the
sphere, lies our own oikumene, and that of the Antoecians
in corresponding longitude and in opposite latitude; on the other hemisphere
lies the oikumene of the Perioecians in our latitude and
in opposite longitude, and that of the Antipodes in latitude and
longitude opposite to us. Through the formulation and expression of such
a theory the existence of an antipodal people was put forth as a speculative
problem, an idea frequently discussed in the Middle Ages, and settled only
by the actual discovery of antipodal regions and antipodal peoples in the
day of great transoceanic discoveries of the 17th and 18th centuries.

A belief in the existence of antipodal peoples, very clearly was also
accepted by Pythagoras, Eratosthenes, Posidonius, Aristotle, Strabo, and
later Capella. Numerous others presupposed the earth to be globular in
shape. [see Kretschmer, K., Die physische Erdkunde im christlichen Mittelalter.
Wien, 1889. pp. 54-59, wherein the author gives consideration to the doctrine
of the
Antipodes as held in the Middle Ages. Berger, Geschichte,
pt. 3, p. 129, notes that the idea of the earth's division into four parts
or quarters persisted for centuries after Crates' day, if not among scientific
geographers, at least among those who could be said to have possessed general
culture. Cleomedes, Ampelius, Nonnus, and Eumenius mention the idea as
one to be accepted.

It was thought that Africa did not extend to the equator, or at least
was not habitable to the equator. Below the equator there was thought to
be water but beyond the uninhabitable and impassable torrid zone, a habitable
region existed. The map of Lambertus well represents this early theory.
Pomponius Mela called the inhabitants of this southern region Antichthoni,
their country being unknown to us because of the torrid zone intervening.
Pliny, and after him Solinus, says that for a long time the island of Taprobana
[Ceylon/Sri
Lanka] was thought to be the region occupied by the Antichthoni.

That Strabo , at a later date, had this Pergamenian example in mind
when stating certain rules to be observed in the construction of globes
seems probable, since he makes mention of Crates' globe. Strabo alone among
ancient writers, so far as we at presently know, treats terrestrial globes
practically. He thought that a globe to be serviceable should be of large
size, and his reasoning can readily be understood, for what at that time
was really known of the earth's surface was small indeed in comparison
with what was unknown. Should one not make use of a sphere of large dimensions,
the habitable regions in comparison with the earth's entire surface, would
occupy but small space. What Strabo states in his geography is interesting
and may here well be cited.

Whoever would represent the real earth as near as possible by artificial
means, should make a sphere like that of Crates, and upon this draw the
quadrilateral within which his chart of geography is to be placed. For
this purpose however a large globe is necessary since the section mentioned,
though but a very small portion of the entire sphere, must be capable of
containing properly all the regions of the habitable earth and of presenting
an accurate view of them to those who wish to consult it. Anyone who is
able will certainly do well to obtain such a globe. But it should have
a diameter of not less than ten feet; those who cannot obtain a globe of
this size, or one nearly as large, had better draw their charts on a plane
surface of not less than seven feet. Draw straight lines for the parallels,
and others at right angles to these. We can easily imagine how the eye
can transfer the figure and extent (of these lines) from a plane surface
to one that is spherical. The meridians of each country on the globe have
a tendency to unite in a single point at the poles; nevertheless on the
surface of a plane map there would be no advantage if the right lines alone
which should represent the meridians were drawn slightly to converge.

Crates' motive for his cartography was partly literary, interpreting
Ulysses' wanderings, and historical rather than purely scientific. As a
Stoic, he proclaimed Homer the founder of geography, crediting him with
belief in a spherical earth and commenting on his poems accordingly. To
explain Homer's line, "The Ethiopians who dwell sundered in twain, the
farthermost of men", Crates argued that on each side of an equatorial ocean
there lived the Ethiopians, divided by the ocean, one group in the Northern
Hemisphere, the other group in the Southern, without any interchange between
them. Again Strabo reports:

Crates, following the mere form of mathematical demonstration, says
that the torrid zone is "occupied" by Oceanus, and that on both sides of
this zone are the temperate zones, the one being on our side, while the
other is on the opposite side of it. Now, just as these Ethiopians on our
side of Oceanus, who face the south throughout the whole length of the
inhabited world, are called the most remote of the one group of peoples,
since they dwell on the shores of Oceanus, so too, Crates thinks, we must
conceive that on the other side of Oceanus also there are Ethiopians, the
most remote of the other group of peoples in the temperate zone, since
they dwell on the shores of this same Oceanus.

The scientific thinking behind the geography of Crates' globe was derived
directly from the teaching of Eratosthenes about the relative size of the
known world. By combining the geometric approach of his predecessor with
his own interpretation of Homer, he represented four inhabited worlds on
the surface of his terrestrial globe. Two were in the Northern Hemisphere,
the one where the Greeks lived, occupying far less than half of the Northern
Hemisphere, and another symmetrically situated in the other half. Two other
inhabited worlds are found in the Southern Hemisphere, symmetrical with
the two north of the equator. These four worlds were separated by oceans
along the equator (occupying the torrid zone made uninhabitable by heat)
and along a meridian. The inhabited areas were thus islands, with no communication
between them.

It is clear that this conception of four symmetrical land areas was
a direct consequence of the geometry of the sphere and the size Eratosthenes
attributed to the inhabited world in relation to the total globe. Crates
demonstrated this by drawing the four areas on the surface of his globe
and suggesting that the three unknown lands could be similar to the known
one. To give it further credibility, he also drew in the main parallel
circles, emphasizing those defining the zones: these were the tropics (at
24° distance from the equator), between which flowed the Ocean as envisaged
by Homer, and the two polar circles (at 66° distance from the equator).

Crates' globe was thus a product of theoretical mathematical cartography,
communicating an image of the world that was very far from reality. Our
understanding of the globe's physical characteristics is meager, and there
is no evidence to suggest how or of what material it was made, but its
influence on the history of cartographic thought has been considerable.
The concept of the equatorial ocean was transmitted to medieval Europe
through Macrobius' commentary on Cicero's Dream of Scipio. Scholars
of later times also vied eagerly to give adequate names to these unknown
worlds, but on the whole they did not doubt their existence.